Page 46 - Zero Net Energy Case Study Buildings-Volume 1

CASE STUDY NO. 2
STEVENS LIBRARY AT SACRED HEART SCHOOLS
PHOTO: BRUCE DAMONTE
Care was taken to detail all conditions where insulation gaps might occur at floor-to-wall and wall-to-roof transitions, and to seal the entire building envelope to prevent unwanted air leaks. This sealing is an essential efficiency measure to keep heating and cooling loads low
The window glazing is a high performance double-glazed system using color-neutral low-e So- larban 70XL coupled with an inner lite of conventional clear glass. This specification provides a low U-value equal to 0.28, a low SHGC (solar heat coefficient) of 0.28, while maintaining a visible light transmittance of 64%.
Daylighting and Electric Lighting
The top-lighting was provided by the introduction of a number of solar tubes at the roof, care- fully located between solar photovoltaic panels to avoid shadowing effects. The high efficiency linear fluorescent direct/indirect light fixtures are continuously dimmed in response to available daylight, although the dimming can be overridden by staff.
Heating, Cooling and Ventilation
The low construction budget dictated a number of decisions about the approach to the HVAC systems in this building. A radiant heating and cooling system using a heat pump and circulating heated or chilled water in the concrete slab is generally a preferred approach for a ZNE build-
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Zero Net Energy Case Study Buildings: Volume 1